PTT Exploration and Production Pcl (PTTEP) , the upstream arm of Thailand’s energy giant PTT Group , said on Thursday that it was delaying plans investment for the Mariana Oil Sands in Canada.

PTTEP, which owns 100 percent of the Mariana Oil Sands, is delaying the project’s final investment decision, which will result in an impairment cost of $550 million, the company said. The cost will be reflected in its third-quarter earnings.

The delay is the latest project to be postponed in Canada’s oil sands, where producers have been holding off on investments because of high start-up costs . The move is also in line with PTT’s strategy of focusing more on midstream capacity and natural gas assets .